Ceramic Materials Containing Volcanic Ash and Characterized by Photoluminescent Activity

The present work was aimed at investigating the possibility to produce bricks using volcanic ash from the Etna volcano and with photoluminescent properties. The volcanic ash was analyzed using X-ray diffractometry, scanning electron and energy dispersive X-ray microscopy. Mixtures with 0%, 10% and 30% of volcanic ash were prepared and fired at 950 °C for 14 h. Their mechanical properties, dynamic modulus of elasticity, drying linear retraction, capillary water absorption and water absorption were measured. The obtained results show that increasing the percentage of volcanic ash in the initial mixture results in a decrease in the measured dynamic modulus of elasticity, in a greater dimensional stability and in a lower weight loss upon firing. Mechanical properties are negatively affected by volcanic ash, with a compressive strength of 11 MPa obtained with mixtures with 30% of it. A decrease in the absorption of water was also observed upon increasing the amount of volcanic ash in the mixes. Brick surfaces with intense photoluminescent activity were obtained. The produced bricks meet the criteria required by the for bricks that can be used in normal weathering and absorption criteria for second-class brick.